Structural Design of Approx. 300kL Suspended Swimming Pool
The scope of this project called for a detailed structural design and coordination with the pool builder to achieve the desired architectural aesthetics whilst maintaining structural integrity of the 35m long 300kL pool, infinity edge, bushfire shelter, mechanical store and large outdoor decking area.
The site is located on Browns Mountain below the upper escarpment crest which overtime had deposited colluvium and talus debris from landslide activity over thousands of years. A geotechnical investigation undertaken by Coffey Geotechnics Pty Ltd indicated that a risk of potential landslip exists on the slope due to the loose nature of the overlying material. Considering these factors in combination with the inherent weight of the pool structure, steel ‘H’ piles were specified to be driven into the underlying weathered bedrock.
Due to the size and capacity of the pool structure, Westlake Punnett & Associates Pty Ltd undertook the detailed analysis and design to AS3735-2001 which outlines increased provisions for concrete swimming pools with a surface area greater than 100m2 or 16.5m in length. Earthquake loads are not normally a design consideration for in-ground pools. However, the location on the slope and the weight of the structure, necessitated that the design withstand loads deriving from Earthquakes in accordance with AS1170.4-2007.
In order to accurately analyse the behaviour of the pool under a variety of loading circumstances, a three dimensional finite element analysis model was used alongside a rigorous static analysis.
The suspended sections of the pool span between structural ‘I’ beams which provide strength to the structure whilst also maintaining the desired aesthetic appeal of the pool when viewed from its down-slope elevation. All other concrete elements were designed to be cast against the ground or formed using traditional timber forms with minimal lost formwork.
The initial site works have commenced on this project and we expect its completion in late 2017.